Peristaltic pumping system



Feb. 25, 1969 c. B. JONES, JR 3,429,266

PERISTALTIC PUMPING SYSTEM lof2 Sheet Filed April 27. 1967 fNVf/VTOQ. CHARLES 5. JONES Jr J W 7 QM 5 flf-QrriEYS all l? Y 1969 c. B. JONES, JR

PERISTALTIC PUMPING SYSTEM Sheet of Filed April 27. 1967 4 N O J Eww 0 w m m N I N 1. 5 Cd m A m 3,429,266 PERISTALTIC PUMPING SYSTEM Charles B. Jones, Jr., Ireland Army Hospital, Fort Knox, Ky. 40121 Filed Apr. 27, 1967, Ser. No. 634,312 U.S. Cl. 103-44 11 Claims Int. Cl. F041) 9/10, 43/00 ABSTRACT OF THE DISCLOSURE A peristaltic pump embodying one or more tubes formed of flexible material, each tube being provided with a plurality of fluid chambers to which fluid may be supplied under pressure and in a sequential manner to compress successive portions of the tubes. Fluid may thus be advanced through the tubes in a predetermined or selective manner by the application of pressure to the successive fluid chambers surrounding the tubes.

RELATED APPLICATION This application is directed to the same general field of invention as applicants copending application Ser. No. 603,935.

BACKGROUND OF THE INVENTION Field of inventin.This invention relates to peristaltic pumps adapted for use in causing fluids to be advanced through one or more flexible tubes in a predetermined manner. Such equipment is widely used in producing and evaluating or analyzing fluids in pathological, medicinal, surgical, chemical, and industrial fields. For this purpose, flexible tubes of the same or diflerent internal diameters are compressed progressively at successive points longitudinally thereof to force the fluid along the tube in a predetermined direction. The amount of the fluid pumped through any tube is dependent upon the cross sectional area of the tube and the rate at which the successive portions of the tube are compressed. Thus, the amount of fluid pumped through each tube can be varied by change in the size of the tube or by varying the speed at which the tube compressing means are moved along the tubes.

Description of the prior art.It has been usual heretofore to provide peristaltic pumps with a base or support upon which a plurality of flexible tubes of predetermined internal diameter are mounted. Rollers or pressure members are then moved into engagement with the tubes and toward the support to collapse and seal all of the tubes at one or more points. The pressure members are at the same time moved longitudinally of the tubes to move the fluid therein lengthwise of all of the tubes simultaneously to discharge predetermined amounts or proportions of fluid from the tubes. Typical peristaltic pumps of the prior art are shown in the following patents: 2,797,149; 2,865,303; 2,935,028; 3,047,367; 3,072,296; 3,079,868; 3,101,674; 3,101,675; 3,116,694; 3,122,103; 3,128,716; 3,227,092; and 3,234,796.

While such pumps are widely used, they present certain serious problems in that it is diflicult if not impossible to vary the rate of flow or the volume of liquid pumped through individual compressible tubes of the same internal diameter. The control of such flow is, therefore, varied by employing tubes of diflerent internal diameter. However, the rate of flow of the diflerent fluids required in many operations varies by relatively small amounts with the result that it is necessary to provide a large number of tubes having different internal diameters and errors in the selection of the proper tubes to be used in any particular operation may have disastrous results. More- 3,429,266 Patented Feb. 25, 1969 over, in many operations, it is desirable to vary the amount or proportion of the fluids being pumped through the various tubes as an operation proceeds in order to control or maintain a predetermined condition such as the pH value, color, density or composition of the mixture of fluids being produced. No such variation or control has been possible heretofore when using equipment of the prior art referred to above or known to the applicant.

SUMMARY OF THE INVENTION In accordance with the present invention, it is possible to use compressible tubes in a peristaltic pump which are all of the same internal diameter or are of a limited number of sizes while at the same time the amount of fluid pumped through each tube may be independently controlled to assure accurate and varied or predetermined flow therethrough to control or vary the composition of a mixture of fluids being produced. It is in fact possible to discontinue or even reverse the direction of flow of fluid through any one or more of a group of tubes employed in the equipment. These results are attained by surrounding each tube, or a group of tubes, with suc cessive fluid pressure chambers to which fluid under pressure may be supplied in a selective or predetermined manner to compress successive portions of the tubes for moving fluids therethrough as desired in any particular operation.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic longitudinal sectional view through a typical form of compressible tube surrounded by pressure chambers, and provided with means for controlling the pressure of fluid supplied to the pressure chambers;

FIG. 2 is a diagrammatic illustration of a form of fluid pressure distributor adapted for use in the system of FIG. 1;

FIGS. 3 to 5 are transverse sectional views through various alternative forms of tubes and pressure chambers adapted for use in the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In that form of the invention chosen for purposes of illustration in FIG. 1 of the drawing, the tube 2 is formed of flexible material and provided with an inlet end 4 and an outlet end 6 adapted respectively to be connected to a suitable source of the fluid to be pumped through the tube 2 and to a mixing or other device or chamber to which the fluid is to be supplied.

A series of pressure chambers 8, 10, 12, 14 and 1 6 are arranged in adjacent positions surrounding the tube 2 and each is supplied with a pressure fluid inlet 18 to which fluid, such as compressed air or liquid may be supplied from a pump 20 through a control device 22. The pressure chambers may be formed of flexible material, such as rubber or the like, and chamber 8, as shown, may be in the form of a hollow sphere through which the tube 2 passes with the spherical chamber 8 sealed to the tube 2 at the points 24 to provide an airtight connection with the tube. The chambers 10, 12, 14 and 16 are in the form of cup-shaped elements which are preferably flexible and adapted to be slipped over the tube 2 lengthwise thereof so as to be brought into direct engagement with one another. The chamber 10 is sealed to the tube 2 at the point 26 and is also sealed to the spherical chamber 8 along the annular line of contact 28. Each of the other cup-shaped chambers 12, 14 and 16 is sealed to the tube 2 at the point 26 and is sealed to the adjacent cup-shaped chamber along a similar line of contact 28. In this way, the chambers 8, 10, 12, 14 and 16 cooperate to provide a series of adjacent airtight chambers surrounding successive portions of the tube 2 throughout any desired length of the tube. It will, of course, be apparent that any suitable number of such adjacent pressure chambers may be applied to the tube 2 and each chamber is provided with its own fluid inlet 18 through which pressure can be applied to the chamber and to the portion of the tube 2 enclosed therein to collapse the tube 2 when desired. Further as shown in FIG. 1, retaining or holding members 30 may be located at the opposite ends of the assembly of pressure chambers to prevent longitudinal expansion thereof which might in turn tend to stretch the tube 2 and vary the internal diameter thereof.

The control device 22 serves to cause fluid pressure to be sequentially applied to the various chambers surrounding the tube 2 and may be in the form of a distributing valve such as that shown by way of example in FIG. 2. Such a valve may embody a cylindrical body 32 rotatable within a housing 34 to which fluid supply tubes 8a, 10a, 12a, etc. are connected and from which pressure tubes 8b, 10b, 1211, etc. extend to the fluid inlets 18 of the various chambers 8, 10, 12, etc. The body 32 of the distributing valve may be rotated by a motor 36 or the like to bring the passages 38 within the body into positions to alternately and successively apply pressure to the various chambers and to exhaust the pressure therefrom as the body 32 is rotated.

The construction thus provided is operable to sequentially and selectively supply fluid under pressure to the various pressure chambers and to maintain each chamber under pressure for a desired length of time before releasing the pressure therein. Therefore, as shown in FIG. 1, pressure is applied to the chambers 8 to an extent suflicient to collapse and seal the portion of the tube 2 enclosed thereby. In this way, the fluid within that portion of the tube 2 which is surrounded by the pressure chambers 10, 12, 14 and 16 is sealed off from the fluid inlet 4. However, when pressure is thereafter applied successively to the chambers 10, 12, 14 and 16 to successively collapse the portions of the tube 2 enclosed thereby fluid will be caused to flow forward through the portion of the tube 2 enclosed by chambers 18 to 16 so as to be discharged through the outlet end 6 of the tube 2. At the same time, release of the pressure applied to chamber 8 will allow additional fluid to be admitted through inlet 4 to the portion of the tube 2 enclosed by the pressure chamber 8 through the inlet end -4 of the tube. Sequential release of the pressure applied to the chambers 10, 12, 14 and 16 will allow fluid to be supplied to each succeeding portion of the tube 2.

This sequential application of fluid pressure to the ad jacent portions of the tube 2 surrounded by the pressure chambers 8 to 16 inclusive serves to advance the fluid within the tube 2 from the inlet end 4 to the outlet end 6 thereof at a rate which is determined by the speed of operation of the control device 22.

Any number of the tubes 2, 2a, 2b, 2c, etc. may be employed for pumping fluids from various sources to a common mixing device 48, or to any other point for utilization. Each tube can be provided with a suitable number of pressure chambers for forcing liquid through the tubes. Moreover, the pressure chambers applied to each fluid conducting tube of the pump can be supplied with pressure fluid from either a common source and distributor or control device 22, or from individually and variably operable control devices as indicated at 22a and 22b. In this way, the amount of each fluid supplied to the mixing device 48, or to any other point, can be accurately controlled as desired while employing tubes 2, 2a, etc, which are of the same internal diameter. On the other hand, the tubes 2, 2a, etc. can be of different but predetermined diameters so that different volumes of each fluid will be delivered by each tube upon identical operation thereof.

Further as shown diagrammatically in FIG. 1, the

motors 36 and 36a, etc. by which the distributors 22, 22a, 221), etc. are actuated may be controlled by a sensing device 42, such as a pH meter, photoelectric cell or the like to speed up or slow down the motors 36, 36a, etc. in a manner to increase or decrease the amount of fluid pump ed through the various tubes 2, 2a, 212, etc. to the mixing device 40. In this way, the pumping operation can be monitored or controlled to produce a mixture of fluids having constant and uniform characteristics or to compensate for any deviation from a predetermined norm to which the sensing device is adapted to respond.

The construction thus provided is extremely accurate and sensitive in operation whereas it is simple in construction and eliminates the need for more than one, or more than a limited number of sizes of fluid conducting tubes in the system.

The form of the tubes employed in equipment embodying the present invention may be varied considerably if desired. Thus, as shown in FIG. 3, the tube 44 may be formed as an extrusion having oppositely extending flanges 46 adapted to be sealed between the opposite halves 48 and 50 of a pressure chamber. The pressure tube 52 may be sealed between the half 48 of the pressure chamber and one of the flanges 46 of the tube 44. A pressure equalizing passage 54 may then be formed in the opposite flange 46 of the tube 44 to assure the desired collapsing of the tube 44 to seal the tube or to pump liquid therethrough as desired. The individual pressure chambers can be established by contractions in the outer halves of the pressure chamber as indicated at 56.

In the further alternative embodiment of the invention illustrated in FIG. 4, a single pressure chamber 60 may be used in combination with a plurality of fluid pumping tubes 62, 64, 66 and 68 of the same or different internal diameters as desired for pumping a plurality of fluids to a given point while using a single pressure distributing device. Pressure can then be applied to the common pressure chamber 60 through a fluid supply tube 70. The construction shown in FIG. 4 further illustrates the manner in which the tubes may be mounted on a fixed or rigid support 72 against which the tubes may be flattened upon the application of fluid pressure to the chamber 60.

FIG. 5 illustrates another form of tube and chamber construction which may be employed in the practice of the present invention. In this construction, the tube 74 and the chamber 76 are integral. The chamber 76 is formed from a web or flange of material 78 which projects from one side of the tube 74 and is wrapped about the tube so as to be spaced from but substantially enclose the tube 74 and be secured to a portion of the tube along the line 80. The pressure supplying inlet 82 for admitting pressure fluid to the chamber 76 thus formed can be located adjacent the sealing line 80 or at any other suitable point in the chamber.

It will be apparent from the foregoing description that peristaltic pumps embodying the present invention can be constructed and operated in various ways to attain various results. By suitable programming of the operation of the control device 22 and by varying the operation thereof, it is possible to produce and maintain consistent pumping operations and is even possible to pump fluids in opposite directions through different tubes or to produce a pulsating action in supplying blood or other fluids to the human system or elsewhere. In view thereof, it should be understood that the particular constructions aud methods of operation of the equipment shown in the drawings and described above are intended to be illustrative only and are not intended to limit the scope of the invention.

I claim:

1. A peristaltic pump embodying a continuous and uniformly flexible tube defining a fluid path of substantially uniform internal cross-section throughout the length thereof, a plurality of chambers for receiving fluid pressure arranged in contact with said tube and located in adjacent positions longitudinally of said tube, and means for selectively supplying fluid under pressure to said chambers to collapse contiguous portions of said flexible tube to move fluid through the tube in a selected manner.

2. A peristaltic pump as defined in claim 1 wherein said chambers are formed of flexible material.

3. A peristaltic pump as defined in claim 1 wherein said chambers are in the form of flexible cup shaped members connected in series to provide a series of fluid tight flexible chambers surrounding adjacent portions of said tube.

4. A peristaltic pump as defined in claim 1 wherein said chambers surround said flexible tube.

5. A peristaltic pump as defined in claim 1 wherein the means for supplying fluid under pressure to said chambers includes a source of fluid under pressure and a distributing valve operable to pass fluid from said source to said chambers in a predetermined sequence.

6. A peristaltic pump as defined in claim 5 wherein fluid from said tube is passed to a mixing device, a sensing means is responsive to a condition developed in said mixing device, and operation of said distributing valve is controlled by said sensing means.

7. A peristaltic pump as defined in claim 1 wherein there are a plurality of said flexible tubes each having a plurality of said chambers in contact therewith, and means are provided for supplying fluid under pressure in a predetermined manner to each of said chambers.

8. A peristaltic pump as defined in claim 7 wherein all of said flexible tubes have the same internal diameter.

9. A peristaltic pump as defined in claim 7 wherein said flexible tubes are of diflerent internal diameter.

10. A peristaltic pump as defined in claim 7 wherein means are provided for simultaneously supplying fluid under pressure to the chambers contacting all of said tubes in the same sequence.

11. A peristaltic pump as defined in claim 7 wherein means are provided for selectively supplying fluid under pressure to the chambers in contact with each tube in a predetermined sequence.

References Cited UNITED STATES PATENTS 2,788,953 4/ 1957 Schneider.

3,154,021 10/1964 Vick 103152 3,359,916 12/1967 Houston et al 103-152 FOREIGN PATENTS 894,503 10/ 1953 Germany.

ROBERT M. WALKER, Primary Examiner.

US. Cl. X.R. 

